Uses
Anti-emetic; antihistaminic.
Definition
ChEBI: A tertiary amine that is a substituted phenothiazine in which the ring nitrogen at position 10 is attached to C-3 of an N,N-dimethylpropan-2-amine moiety.
Brand name
Phenergan (Wyeth).
General Description
Crystals. Melting point 60°C. Used as an antihistaminic.
Air & Water Reactions
Turns blue on prolonged exposure to air and moisture.
Reactivity Profile
PROMETHAZINE neutralizes acids in exothermic reactions to form salts plus water. May be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Flammable or toxic gases may be generated in combination with strong reducing agents, such as hydrides.
Health Hazard
SYMPTOMS: Symptoms of PROMETHAZINE include leucopenia; agranulocytosis; confusion; convulsions; stupor; and it potentiates the action of central nervous system depressants.
Fire Hazard
Flash point data for PROMETHAZINE are not available, however PROMETHAZINE is probably combustible.
Description
As a derivative of phenothiazine, promethazine is structurally and pharmacologically similar
to chlorpromazine. It exhibits strong antihistamine activity as well as expressed action
on the CNS. It potentiates action of sedative and analgesic drugs.
World Health Organization (WHO)
Introduced in 1946, promethazine, a phenothiazine derivative has
a variety of pharmacological properties. At present it is mainly used as an
antihistamine and anti-motion-sickness drug. Promethazine is listed in the WHO
Model List of Essential Drugs.
Clinical Use
Promethazine, an early agent in the series, has many useful pharmacological affects other
than being an antihistamine. It has significant antiemetic and anticholinergic properties. It
also has sedative-hypnotic properties and has been used to potentiate the effects of
analgesic drugs. Subsequent analogues, such as trimeprazine and methdilazine, are used as
antipruritic agents in the treatment of urticaria.
Synthesis
Promethazine, 10-(2-dimethylaminopropyl)phenothiazine (16.1.18), is
synthesized by alkylating phenothiazine with 1-dimethylamino-2-propylchloride.
